sort local tasks

Closes #2219393

core/lib/Drupal/Core/Menu/LocalTaskManager.php

@@ -360,6 +360,17 @@ public function getLocalTasks($route_name, $level = 0) {
         foreach ($local_tasks as $tab_level => $items) {
           $data[$tab_level] = empty($data[$tab_level]) ? $items : array_merge($data[$tab_level], $items);
         }
+
+        // Sort by weight and alphabetically if weights are the same.
+        foreach ($data as $key => $values) {
+          $weights = array_column($values, '#weight');
+          array_multisort(
+            $weights, SORT_ASC, SORT_NUMERIC,
+            array_keys($values), SORT_ASC, SORT_NATURAL,
+            $data[$key],
+          );
+        }
+
         $this->taskData[$route_name]['tabs'] = $data;
         // Allow modules to alter local tasks.
         $this->moduleHandler->alter('menu_local_tasks', $this->taskData[$route_name], $route_name, $cacheability);